Portable pneumatic stay-bolt cutter.



A. M. BAIRD. I PORTABLE PNEUMATIC STAY BOLT CUTTER. APPLICATION FILED MAY 23, 1914.

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A. M. BAIRD.

PORTABLE PNEUMATIC STAY BOLT CUTTER, APPLICATION FILED MAY 23, 1914.

Lmgflm. v Patented Feb. 23, 1915.

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PORTABLE PNEUMATIC STAY-BOLT CUTTER.

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Specification of Letters Patent.

Patented Feb. 23, 1915.

Application filed May 23, 1914. Serial No. 840,498.

the stay-bolt cutter both more powerful and shorter, compactness beingessential to the greatest range of usefulness of such a device in order to cut the stay-bolts in places that are inaccessible by machines of a great bulk or length.

A further object is to'improve upon the manner of pivoting the cutting'jaw levers, so as to relieve the frame proper of much of the burden of the strain incident to the operation of the jaws, making it possible to lighten the construction of the machine.

Further objects will'appear hereinafter.

My invention comprises the parts, improvements, and combinations relating to these objects, as hereinafter set forth and claimed.

In the drawings I have shown my invention in its preferred form and what I deem to be the best mode of applying the principles thereof; but it is to be understood that, within the scope of the appended claims, I contemplate changes in form, proportions, and materials, the transposition of parts, and the substitution of equivalent members, without departing from the spirit of my invention.

Figure 1 is an elevation of a stay-bolt cutter made in accordance with the principles of my invention, the left-hand half be ing a vertical central sectional. elevation. Fig. 2 is another elevation taken at right angles to Fig. 1. Fig. 3 is a transverse section on a plane indicated by the line 3 in Fig. 1. Fig. 1 is an end view of the piston rod showing especially the cross-head.

Similar reference characters indicate simi lar parts throughout the several views.

5 is the cylinder; 6 is the piston working therein; and 7 is the piston rod.

8, 8 are two standards formed integrally with the cylinder casing and extending aXially thereof and formed with bosses 9, 9 at their outer ends, between which is extended a pivot pin or bolt 10. 11, 12 are the two levers for operating the cutting jaws; they are formed with male and female parts 14: and 13 respectively pivoted to said pin between said bosses, so that the movement of the levers away from each other moves the cutting jaws 15 toward each other, and vice versa. lhe cutting jaws are formed sepa rately from the levers, round in cross-section, with flattened end portions 16, and lit into correspondingly shaped sockets in the projecting ends of the levers, being held therein by means of set-screws 17 provided with lock nuts 18. The flattened faces 16 prevent the cutting jaws from being twisted in their sockets. The ends of the levers opposite the cuttingjaws terminate close to the cylinder casing,as closely as working conditions will permit. On each side of each such end is a. link 19, pivoted by means of pinsor bolts 20, the other ends of the links being pivoted in the respective sockets 23,23, 28, 23, formed in the cross-head 22, and by means of the pivot pins or bolts 21.

2 1 is an extension spring secured at one end to a loop 25 formed in the cross-head and at the other end to a screw-eye 26 screwed into the male member 14.

27 is a fluid-pressure supply pipe to supply the motive fluid to the cylinder to operate the piston in one direction; and 28 is a three-way cock to control the flow.

29 is a bail or yoke pivoted to the lugs 30, 30 secured to the cylinder casing, by means of the pivot pins or bolts 31, in such way that the machine is balanced on said pivots.

32 is a rubber gasket mounted on the piston rod between the cross-head and the cylinder casing, its purpose being to absorb the shock at the end of the cutting stroke.

By pivoting both levers to the common pivot bolt, the frame is relieved of the lateral strain incident to the working of the cutting jaws, and need be only of suliicient weight and strength to hold the pivot pin and withstand the relatively much less compressive strain incident to such working. The arrangement of the links forms a toggle-joint operated by the piston and piston rod in such way that the working stroke is away from the pivot pin 10 and the stroke becomes most powerful at its end. This arrangement also permits the ends of the levers to be brought close to the cylinder casing, thus greatly shortening the machine as a whole. By means of the balanced suspension on the yoke, the machine is easily handled in guiding the cutting jaws to the stay-bolts. The yoke is intended for suspension above the work by means of a suitable blockand tackle.

The operation of the stay-bolt cutter is controlled by the handle of the three-way cock, the fluid actuating the piston and connected parts for the cutting stroke, and the spring restoring the parts to normal posi tion ready for the next cutting stroke. The arrangement of the spring is such that no extra length is added to the machine 'on account of the spring.

Having thus described my invention, what I claim .as new and desire to-secure by Letters Patent is:

1. The combination of a cylinder casing formed with two pivot standards, a pivot pin between the ends of the standards, two levers pivoted between their ends on said pin the outer ends of said levers being formed with cutting jaws and the inner ends terminating close to the cylinder casing, a piston in the cylinder, a piston rod terminating in a cross-head between said two inner ends, and two pairs of links the links of one pair being pivoted at one end on opposite sides of one of said inner lever ends and at the other end to said crosshead, and the links of the other pair being pivoted at one end on opposite sides of the other of said inner lever ends and at the other end to said cross-head.

2. The combination of a cylinder casing formed with two pivot standards on opposite sides of the prolonged axis of said cylinder casing, a pivot pin secured to and extending between the outer ends of said standards, two levers pivoted on said pivot pin and formed at their outer ends with cutting jaws and terminating at their inner ends adjacent the cylinder casing, a piston, a piston rod, a toggle-jointed element connecting said inner ends with the piston rod for closing the cutting jaws by movement of the piston and piston rod away from the pivot pin,-and an extension spring extending axially of the cylinder between the piston rod and the pivot pin for moving the said parts in the opposite direction.

3. The combination of a cylinder casing formed with two pivot standards on opposite sides of the prolonged axis of said cylinder casing, a pivot pin secured to and extending between the outer ends of said standards, two levers pivoted on said pivot pin and formed at their outer ends with cutting jaws and terminating at their inner ends adjacent the cylinder casing, a piston, a piston rod having a cross-head, a togglejointed element between the inner ends of the levers and the cross-head for closing the jaws on movement of the piston away from the pivot pin, and a rubber gasket mounted on the piston rod between the cross-head and the cylinder casing for absorbing the shock at the end of the cutting stroke.

4. In a device of the kind described, the combination of a frame, levers pivoted to each other, means for operating the levers, detachable cooperating cutting jaws, each being formed with a round shank and each shank being formed with a flattened portion, the levers being formed at their respective ends with sockets for holding said shanks with said flattened portions bearing against the pivot.

5. The combination of a cylinder, pivot standards secured thereto, two levers pivoted to the pivot standards their outer ends being formed with cutting jaws and their inner ends terminating close to the cylinder, a piston in the cylinder, a piston rod terminating in a cross-head between said two inner ends, and links connecting the respective inner ends with the respective ends of the cross-head, the connections with the cross-head being spaced apart from each other and on opposite sides of the piston rod.

6. The combination of a cylinder casing formed with axially extending pivot standards, levers with cutting jaws pivoted to said standards, a piston, piston rod, and a toggle-jointed element connecting the piston rod with the levers for operating the same, brackets secured to the cylinder casing and extending axially of the cylinder on opposite sides respectively of the piston rod, and a yoke pivotally connected to said brackets in such manner that said first-named parts are held in balanced suspension by said yoke.

In testimony whereof I have aflixed my signature in presence of two witnesses.

ARCHIE M. BAIRD. Witnesses C. J. RosEN, J. M. STARK.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

